Evolution

Page
1

Slide 1

 

Evolution

Slide 2

 

Definitions

Evolution: the change in frequency of genes within a population

Population: is all the individuals of a species that live in an area

Variation: heritable differences that exist in a population

Adaptation: a variation that allows an individual to survive better than other individuals

Slide 3

 

Important Considerations

Individuals CANNOT evolve. Only populations can evolve.

The most successful members of a population are the ones that have the most surviving offspring. They have made the greatest contribution to the gene pool.

Slide 4

 

What Could Cause Gene Frequencies to Change?

Natural Selection

Migration

Random mutations

Accidents (within small populations)

Artificial Selection

Genetic Engineering

Slide 5

 

Case Study: Antibiotic Resistant Bacteria

Antibiotics are drugs that kill bacteria by interfering with their metabolic processes

The first antibiotic was penicillin, and became available for medical use during WWII.

Certain genes may confer antibiotic resistance upon a bacteria.

Antibiotic resistant bacteria are becoming a medical emergency

Slide 6

 

Antibiotic Resistance #1

A population of bacteria.

Prescription: Treatment with an antibiotic

Slide 7

 

Antibiotic Resistance #2

A population of bacteria after first treatment with an antibiotic

Slide 8

 

Antibiotic Resistance #3

The population of bacteria recovers

Prescription: Antibiotic at a higher dose

Slide 9

 

Antibiotic Resistance #4

The population of bacteria after a second course of the antibiotic

Slide 10

 

Antibiotic Resistance #5

The population of bacteria recovers

Prescription: A different antibiotic

Slide 11